使用高螺距70kV胸部CT评估免疫抑制患者的辐射剂量和图像质量。

Evaluation of Radiation Dose and Image Quality using High-Pitch 70-kV Chest CT in Immunosuppressed Patients.

作者信息

Yel Ibrahim, Martin Simon S, Wichmann Julian L, Lenga Lukas, Albrecht Moritz H, Bucher Andreas M, Kaltenbach Benjamin, Polkowski Christoph, Booz Christian, Vogl Thomas J, Hammerstingl Renate Maria

机构信息

Department of Diagnostic and Interventional Radiology, University-Hospital Frankfurt, Germany.

出版信息

Rofo. 2019 Feb;191(2):122-129. doi: 10.1055/a-0668-6031. Epub 2018 Sep 4.

DOI:10.1055/a-0668-6031

PMID:30180261

Abstract

PURPOSE

The aim of the study was to evaluate high-pitch 70-kV CT examinations of the thorax in immunosuppressed patients regarding radiation dose and image quality in comparison with 120-kV acquisition.

MATERIALS AND METHODS

The image data from 40 patients (14 women and 26 men; mean age: 40.9 ± 15.4 years) who received high-pitch 70-kV CT chest examinations were retrospectively included in this study. A control group (n = 40), matched by age, gender, BMI, and clinical inclusion criteria, had undergone standard 120-kV chest CT imaging. All CT scans were performed on a third-generation dual-source CT unit. For an evaluation of the radiation dose, the CT dose index (CTDIvol), dose-length product (DLP), effective dose (ED), and size-specific dose estimates (SSDE) were analyzed in each group. The objective image quality was evaluated using signal-to-noise (SNR) and contrast-to-noise ratios (CNR). Three blinded and independent radiologists evaluated subjective image quality and diagnostic confidence using 5-point Likert scales.

RESULTS

The mean dose parameters were significantly lower for high-pitch 70-kV CT examinations (CTDIvol, 2.9 ± 0.9 mGy; DLP, 99.9 ± 31.0 mGyxcm; ED, 1.5 ± 0.6 mSv; SSDE, 3.8 ± 1.2 mGy) compared to standard 120-kV CT imaging (CTDIvol, 8.8 ± 3.7mGy; DLP, 296.6 ± 119.3 mGyxcm; ED, 4.4 ± 2.1 mSv; SSDE, 11.6 ± 4.4 mGy) (P≤ 0.001). The objective image parameters (SNR: 7.8 ± 2.1 vs. 8.4 ± 1.8; CNR: 7.7 ± 2.4 vs. 8.3 ± 2.8) (P≥ 0.065) and the cumulative subjective image quality (4.5 ± 0.4 vs. 4.7 ± 0.3) (p = 0.052) showed no significant differences between the two protocols.

CONCLUSION

High-pitch 70-kV thoracic CT examinations in immunosuppressed patients resulted in a significantly reduced radiation exposure compared to standard 120-kV CT acquisition without a decrease in image quality.

KEY POINTS

· Third-generation dual-source CT units enable high-pitch 70-kV CT examinations of the chest.. · High-pitch 70-kV CT examinations show a significantly reduced radiation dose compared to standard 120-kV CT examinations.. · High-pitch 70-kV CT examinations of the chest show comparable objective and subjective image quality.. · Subjectively deteriorated image noise and sharpness of 70-kV CT did not impact diagnostic confidence..

CITATION FORMAT

· Yel I, Martin SS, Wichmann JL et al. Evaluation of Radiation Dose and Image Quality using High-Pitch 70-kV Chest CT in Immunosuppressed Patients . Fortschr Röntgenstr 2019; 191: 122 - 129.

摘要

目的

本研究旨在评估免疫抑制患者胸部的70 kV高螺距CT检查在辐射剂量和图像质量方面与120 kV采集相比的情况。

材料与方法

本研究回顾性纳入了40例接受70 kV高螺距胸部CT检查的患者（14名女性和26名男性；平均年龄：40.9±15.4岁）。一个由年龄、性别、BMI和临床纳入标准匹配的对照组（n = 40）接受了标准的120 kV胸部CT成像。所有CT扫描均在第三代双源CT设备上进行。为了评估辐射剂量，分析了每组的CT剂量指数（CTDIvol）、剂量长度乘积（DLP）、有效剂量（ED）和尺寸特异性剂量估计值（SSDE）。使用信噪比（SNR）和对比噪声比（CNR）评估客观图像质量。三名不知情且独立的放射科医生使用5点李克特量表评估主观图像质量和诊断信心。

结果

与标准120 kV CT成像相比，70 kV高螺距CT检查的平均剂量参数显著更低（CTDIvol，2.9±0.9 mGy；DLP，99.9±31.0 mGyxcm；ED，1.5±0.6 mSv；SSDE，3.8±1.2 mGy）（CTDIvol，8.8±3.7 mGy；DLP，296.6±119.3 mGyxcm；ED，4.4±2.1 mSv；SSDE，11.6±4.4 mGy）（P≤0.001）。客观图像参数（SNR：7.8±2.1对8.4±1.8；CNR：7.7±2.4对8.3±2.8）（P≥0.065）和累积主观图像质量（4.5±0.4对4.7±0.3）（p = 0.052）在两种方案之间没有显著差异。